Feature #12300: Allow Object#clone to take freeze: false keyword argument to not freeze the clone

• Status: Closed
• Assignee: -
• Target version: -

[jeremyevans0 (Jeremy Evans)]

This allows Object#clone to not freeze the resulting object, which fixes a long standing problem in ruby in that you cannot get an unfrozen copy of an object that includes a copy of the object's singleton class. Previously, clone always returned a frozen object, and dup did not copy the singleton class. This adds the ability to get an unfrozen clone of an object that includes a copy of the object's singleton class, allowing further modification.

Among other things, this allows the ability to create modified clones of objects that have singleton classes:

class A
  def clone(arg)
    obj = super(freeze: false)
    # modify obj based on arg
    obj.freeze
  end
end

I think this is a simpler and more flexible approach to the same problem that #12092 tries to solve.

[shyouhei (Shyouhei Urabe)]

Sounds much simpler than the previous one to understand what is happening. Also it seems backwards-compatible.

Given the needs of this kind, I'd like to +1.

[matz (Yukihiro Matsumoto)]

Sounds reasonable.

Matz.

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Closed

Applied in changeset r55786.

---

Object#clone with freeze: false [Feature #12300]

* object.c (rb_obj_clone2): Allow Object#clone to take freeze:
  false keyword argument to not freeze the clone.
  [ruby-core:75017][Feature #12300]

* test/ruby/test_object.rb (TestObject): test for it.